MATH 534 Week 4 Homework Problems Keller Devry University

1. Arandomsampleof100selectedfromapopulationwithastandarddeviation of 10 yielded a mean = 225. The mean and the standarddeviationofthedistributionofthesamplemeansare . 2. Suppose a random sample of 49 is selected from a population ofsize N = 500 with a standard deviation of 14. If the sample mean is125,the99%confidenceintervaltoestimatethepopulationmeanisbetween . 3. A manufacturer wants to purchase a certain product of foil. The foilisstoredon1534rollseachcontainingavaryingamountoffoilwithastandard deviation of 12.5. In order to estimate the total number of foilonall the rolls, the manufacturerrandomlyselected 200rolls andmeasuredthenumberoffoiloneachroll.Thesamplemeanwas48.Thenthe95%confidenceintervaltoestimatethepopulationmeanoffoilisbetween . 4. Supposearesearcherisinterestedinunderstandingthevariationinthe price of store brand milk. A random sample of 36 grocery storesselectedfromapopulationandthemeanpriceofstorebrandmilkiscalculated.Thesamplemeanis$3.13withastandarddeviationof 5. Supposearesearcherisinterestedinunderstandingthevariationinthe price of store brand milk. A random sample of 36 grocery storesselected from a population and the mean price of store brand milk iscalculated. The sample mean is $3.13 with a population standarddeviationof$0.25.Constructa95%confidenceintervaltoestimatethepopulationmean.